Carrier switching method, apparatus, and system for multi-carrier communication

ABSTRACT

This application discloses a carrier switching solution for multi-carrier communication. A network device sends configuration information to a terminal. The configuration information includes first uplink carrier information and second uplink carrier information. The first uplink carrier information indicates that a first uplink carrier is an SRS switching-from uplink carrier. The second uplink carrier information indicates that a second uplink carrier is an SRS switching-to uplink carrier. At least one of the first uplink carrier and the second uplink carrier belongs to a cell including a supplementary uplink (SUL) carrier. The terminal may determine the SRS switching-from uplink carrier and the SRS switching-to uplink carrier in a plurality of configured uplink carriers based on the configuration information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/116032, filed on Nov. 16, 2018, which claims priority toChinese Patent Application No. 201711148290.4, filed on Nov. 17, 2017.The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of communications technologies,and in particular, to a multi-carrier communications technology in awireless communications system.

BACKGROUND

A sounding reference signal (SRS) is introduced into a long termevolution (LTE) system. For example, the SRS may be used to determineuplink channel quality. In multi-carrier communication, for example, ina carrier aggregation (CA) scenario, a network device (for example, abase station) configures N component carriers (CC) for a terminal (forexample, user equipment (UE)), and the UE may support simultaneoustransmission of only M (M<N) uplink carriers due to an insufficientuplink capability. Therefore, to obtain downlink channel statuses of N-Mtime division duplex (TDD) carriers of the UE, the SRS is transmitted onthe N-M TDD carriers in LTE Rel-14. In other words, SRS carrierswitching is supported. The UE may switch from one of the M uplinkcarriers (which may be referred to as a switching-from uplink carrier(switching-from UL CC)) to a TDD carrier of the N-M carriers (which maybe referred to as a switching-to uplink carrier (switching-to UL CC)) tosend the SRS.

To make full use of an uplink resource of the LTE system, uplinkresource sharing is discussed, and a shared uplink resource may beconsidered as a supplementary uplink (SUL) resource.

SUMMARY

Embodiments of this application provide a wireless communication method,a wireless communications apparatus, and a wireless communicationssystem, to specify a switching-from uplink carrier for an SRS carrierswitching and a switching-to uplink carrier for the SRS carrierswitching for a cell including an SUL carrier, thereby improvingreliability of SRS transmission.

According to a first aspect, an embodiment of this application providesa wireless communication method and a wireless communications apparatus.The communications apparatus may be, for example, an integrated circuit,a terminal, a wireless device, or a circuit module. The communicationsapparatus receives configuration information that includes first uplinkcarrier information and second uplink carrier information, anddetermines an SRS switching-from uplink carrier and an SRS switching-touplink carrier based on the configuration information. The first uplinkcarrier information indicates that a first uplink carrier is theswitching-from uplink carrier for the SRS carrier switching. The seconduplink carrier information indicates that a second uplink carrier is theswitching-to uplink carrier for the SRS carrier switching.

In solutions of this application, an uplink carrier in a cell includingan SUL carrier (sometimes referred to as an SUL cell) is used as theswitching-from uplink carrier (switching-from UL CC) for an SRS carrierswitching. The communications apparatus may determine whether to use aresource (for example, an RF capability) of the SUL or a resource (forexample, an RF capability) of a non-SUL (sometimes also referred to as aprimary uplink (PUL)). When the SUL cell is used as the switching-touplink carrier (switching-to UL CC) for the SRS carrier switching, thecommunications apparatus may determine whether to switch to the SULcarrier or the non-SUL carrier to transmit an SRS, thereby ensuringreliability of SRS transmission.

Optionally, the communications apparatus is configured to receive DCIthat carries aperiodic A-SRS trigger indication information and uplinkcarrier identifier information, and the A-SRS trigger indicationinformation is used to indicate a specific uplink carrier on which anA-SRS is triggered.

Optionally, an A-SRS switching-to uplink carrier is determined based onthe second uplink carrier information, the A-SRS trigger indicationinformation, and the uplink carrier identifier information. In a specialSRS scenario, the communications apparatus may also determine the SRSswitching-from uplink carrier and the SRS switching-to uplink carrier.Therefore, the communications apparatus can be applied to morescenarios.

The communications apparatus may include a corresponding module or meansconfigured to execute the foregoing method design, and the module or themeans may be software and/or hardware.

In a design, the communications apparatus according to the first aspectincludes a receiving module and a determining module. The receivingmodule is configured to receive the configuration information. Theconfiguration information includes the first uplink carrier informationand the second uplink carrier information. The first uplink carrierinformation is used to indicate that the first uplink carrier is theswitching-from uplink carrier for the SRS carrier switching, and thesecond uplink carrier information is used to indicate that the seconduplink carrier is the switching-to uplink carrier for the SRS carrierswitching. At least one of the first uplink carrier and the seconduplink carrier belongs to the cell including a supplementary uplink SULcarrier. The determining module is configured to determine the SRSswitching-from uplink carrier and the SRS switching-to uplink carrierbased on the first uplink carrier information and the second uplinkcarrier information in the configuration information.

Optionally, the receiving module is further configured to receive thedownlink control information DCI. The DCI carries the aperiodic soundingreference signal A-SRS trigger indication information and the uplinkcarrier identifier. The uplink carrier identifier is used to indicatethe second uplink carrier.

Optionally, that the determining module determines the SRS switching-touplink carrier based on the configuration information includes that thedetermining module determines the SRS switching-to uplink carrier basedon the second uplink carrier information, the A-SRS trigger indicationinformation, and the uplink carrier identifier information.

According to a second aspect, an embodiment of this application providesa wireless communication method and a wireless communications apparatus.The communications apparatus may be, for example, an integrated circuit,a network device (for example, a base station), a wireless device, or acircuit module. A communications apparatus sends SRS configurationinformation that includes first uplink carrier information and seconduplink carrier information. The configuration information includes thefirst uplink carrier information and the second uplink carrierinformation. The first uplink carrier information is used to indicatethat a first uplink carrier is a switching-from uplink carrier for anSRS carrier switching, and the second uplink carrier information is usedto indicate that a second uplink carrier is a switching-to uplinkcarrier for the SRS carrier switching. At least one of the first uplinkcarrier and the second uplink carrier belongs to a cell including asupplementary uplink (SUL) carrier.

Optionally, the communications device is further configured to senddownlink control information (DCI). The DCI carries aperiodic soundingreference signal A-SRS trigger indication information and an uplinkcarrier identifier. The uplink carrier identifier is used to indicatethe second uplink carrier.

The communications apparatus may include a corresponding module or meansconfigured to execute the foregoing method design, and the module or themeans may be software and/or hardware.

In a design, the communications apparatus according to the second aspectincludes a sending module. The sending module is configured to send theconfiguration information of the SRS. The configuration informationincludes the first uplink carrier information and the second uplinkcarrier information.

The first uplink carrier information is used to indicate that the firstuplink carrier is the switching-from uplink carrier for the SRS carrierswitching, and the second uplink carrier information is used to indicatethat the second uplink carrier is the switching-to uplink carrier forthe SRS carrier switching. The at least one of the first uplink carrierand the second uplink carrier belongs to the cell including thesupplementary uplink (SUL) carrier.

Optionally, the sending module is further configured to send thedownlink control information DCI. The DCI carries the aperiodic soundingreference signal A-SRS trigger indication information and the uplinkcarrier identifier. The uplink carrier identifier is used to indicatethe second uplink carrier.

Optionally, the communications apparatus may further include a receivingmodule, configured to receive uplink information sent by a terminal.

Optionally, in the foregoing aspects, at least one of the first uplinkcarrier information and the second uplink carrier information includes acell identifier and the uplink carrier identifier. The SUL cell includesa plurality of uplink carriers (for example, two uplink carriers), andboth the cell identifier and the uplink carrier identifier are addedinto the first uplink carrier information and/or the second uplinkcarrier information. Therefore, it can be determined that which uplinkcarrier in a cell is the SRS switching-from uplink carrier and/or theSRS switching-to uplink carrier.

Optionally, in the foregoing aspects, if a cell to which the seconduplink carrier belongs is the cell including the SUL, the second uplinkcarrier is a non-SUL (sometimes also referred to as a primary uplinkprimary uplink, a secondary uplink, or the like) carrier. For an SULcell that includes a TDD carrier and an SUL carrier, the SUL carrier anda downlink carrier of the TDD carrier are at different frequencies, anddo not have channel reciprocity. For an SUL cell in which there is nophysical uplink shared channel (PUSCH)/physical uplink control channel(PUCCH) transmission, a downlink channel condition of the SUL cellcannot be obtained by using the SRS configured on an SUL carrier.Therefore, when neither of two UL CCs of the SUL cell is configured witha PUSCH/PUCCH, it may be predefined that the switching-to UL CC is thenon-SUL carrier (for example, by using a protocol agreement, throughpre-configuration, or in another manner), to obtain the downlink channelcondition of the SUL cell by using the configured SRS.

Optionally, in the foregoing aspects, if a serving cell to which thefirst uplink carrier belongs is the cell including the SUL, the firstuplink carrier is a non-PUCCH carrier (sometimes also referred to as aPUCCH-less carrier), to avoid an impact on the PUCCH.

Optionally, in the foregoing aspects, the at least one of the firstuplink carrier information and the second uplink carrier information isa new carrier indicator field NCIF identifier, and the NCIF identifieris used to indicate the first uplink carrier and/or the second uplinkcarrier. There are various manners for configuring the NCIF identifier.In an SUL cell scenario, the SRS switching-from uplink carrier and theSRS switching-to uplink carrier may be flexibly indicated.

Optionally, in the foregoing aspects, the NCIF identifier includes acell identifier and the uplink carrier identifier. The NCIF identifierincludes not only the cell identifier but also the uplink carrieridentifier. Therefore, the SRS switching-from uplink carrier and/or theSRS switching-to uplink carrier are/is specifically determined in a cellbased on an NCIF identifier.

Optionally, in the foregoing aspects, the configuration information isfurther used to indicate a location of an uplink carrier in aninformation block of UE-group-level DCI, the uplink carrier is not usedto transmit a PUSCH/PUCCH (for example, a non-PUSCH/PUCCH carrier, or aPUSCH/PUCCH-less carrier), and the information block of theUE-group-level DCI includes at least one of SRS power controlinformation, A-SRS trigger indication information, and uplink carrieridentifier information of the uplink carrier that is not used totransmit the PUSCH/PUCCH. The configuration information only needs toindicate the location of the uplink carrier in the information block ofthe UE-group-level DCI, where the uplink carrier is not used to transmitthe PUSCH/PUCCH. In this case, UE may determine, based on information inthe information block, the switching-from uplink carrier for the SRScarrier switching and/or the switching-to uplink carrier for the SRScarrier switching, thereby reducing overheads for the configurationinformation.

Optionally, in the foregoing aspects, the configuration informationfurther includes an index of a set to which the uplink carrier that isnot used to transmit the PUSCH/PUCCH belongs and an index of a carrierin the set. When there are a large quantity of uplink carriers that arenot used to transmit the PUSCH/PUCCH, the uplink carriers that are notused to transmit the PUSCH/PUCCH may be grouped, and the index of theset and the index of the carrier in the set are configured in theconfiguration information, so that the UE can quickly determine, basedon the set index and the carrier index in the set, the SRSswitching-from uplink carrier and/or the SRS switching-to uplinkcarrier.

According to a third aspect, an embodiment of this application providesa communications apparatus. The communications apparatus includes aprocessor and instruction(s) that is/are stored in a memory and that mayrun on the processor. When the processor executes the instructions, thecommunications apparatus implements the method in any one of embodimentsof the first aspect or the second aspect. Optionally, the communicationsapparatus may include a transceiver unit.

According to a fourth aspect, this application provides a computerstorage medium, including instruction(s). When the instructions run on acomputer, the computer performs the method in any one of embodiments ofthe first aspect or the second aspect.

According to a fifth aspect, this application provides a computerprogram product. When the product runs on a computer, the computerperforms the methods in the foregoing aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a possible radio access networkaccording to an embodiment of this application;

FIG. 2 is a schematic diagram of an architecture example of acommunications system;

FIG. 3 is a schematic diagram of an SRS carrier switching solution;

FIG. 4 is a flowchart of a wireless communication method according to anembodiment of this application;

FIG. 5 to FIG. 9 are schematic diagrams of an SRS carrier switchingsolution;

FIG. 10 is a schematic diagram of an SUL cell that includes a pluralityof NCIF identifiers;

FIG. 11 is a flowchart of a wireless communication method according toanother embodiment of this application;

FIG. 12 is a schematic structural diagram of a network device accordingto this application; and

FIG. 13 is a schematic structural diagram of a terminal according tothis application.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following describes the embodiments of this application withreference to accompanying drawings in the embodiments of thisapplication.

Technologies described in this application may be used in variouswireless communications networks, such as a code division multipleaccess (CDMA) network, a time division multiple access (TDMA) network, afrequency division multiple access (FDMA) network, an orthogonalfrequency division multiple access (OFDMA) network, a single-carrierfrequency division multiple access (SC-FDMA) network, and anothernetwork. Radio technologies such as universal terrestrial radio access(UTRA) and CDMA2000 can be implemented in the CDMA network. The UTRAincludes wideband code division multiple access (WCDMA), the CDMA, andanother variation. Radio technologies such as global system for mobilecommunications (GSM) can be implemented in the TDMA network. Radiotechnologies such as evolved UTRA (E-UTRA), ultra mobile broadband(UMB), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), and IEEE 802.20 can beimplemented in the OFDMA network. The E-UTRA may include a plurality ofversions, such as LTE and LTE-A. This application may be further appliedto a 5G network, a subsequent evolved network, or convergence of variousnetworks.

FIG. 1 is a schematic diagram of a possible radio access network (RAN)according to an embodiment of this application. The RAN includes one ormore network devices 20. The radio access network may be connected to acore network (CN). The network device 20 may be any device with wirelesssending and receiving functions. The network device 20 includes but isnot limited to a base station (for example, base station BS, NodeB, anevolved NodeB, eNodeB or eNB, gNodeB or gNB in the 5th generation 5Gcommunications system, a base station in a future communications system,or an access node, a wireless relay node, or a wireless backhaul node ina Wi-Fi system), and the like. The base station may be a macro basestation, a micro base station, a femto base station, a small cell, arelay station, or the like. A plurality of base stations can supportnetworks in which a same technology mentioned above is used, or maysupport networks in which different technologies mentioned above areused. The base station may include one or more co-site or non-co-sitetransmission reception points (TRP). The network device 20 mayalternatively be a radio controller, a centralized unit (CU), or adistributed unit (DU) in a cloud radio access network (CRAN) scenario.The network device 20 may alternatively be a server, a wearable device,a vehicle-mounted device, or the like. That the network device 20 is abase station is used as an example for description in the following. Theplurality of network devices 20 may be base stations of a same type orbase stations of different types. The base station may communicate witha terminal 10, or may communicate with the terminal 10 by using a relaystation. The terminal 10 may communicate with a plurality of basestations using different technologies. For example, the terminal maycommunicate with a base station supporting an LTE network, maycommunicate with a base station supporting a 5G network, or may supporta dual connection between a base station in an LTE network and a basestation in a 5G network.

The terminal 10 is a device with wireless sending and receivingfunctions. The terminal 10 may be deployed on land and includes anindoor or outdoor device, a hand-held device, a wearable device, or avehicle-mounted device; may be deployed on a water surface (for example,a ship); or may be deployed in the air (for example, an airplane, aballoon, or a satellite). The terminal device may be a mobile phone, atablet computer (Pad), a computer having wireless sending and receivingfunctions, a virtual reality (VR) terminal device, an augmented reality(AR) terminal device, a wireless terminal related to industrial control,a wireless terminal related to self driving, a wireless terminal relatedto telemedicine, a wireless terminal related to a smart grid, a wirelessterminal related to transportation safety, a wireless terminal relatedto a smart city, a wireless terminal related to a smart home, or thelike. An application scenario is not limited in the embodiments of thisapplication. Sometimes, the terminal may also be referred to as aterminal device, user equipment (UE), an access terminal device, a UEunit, a UE station, a mobile site, a mobile station, a remote station, aremote terminal device, a mobile device, a UE terminal device, awireless communications device, a UE agent, a UE apparatus, or the like.The terminal may alternatively be fixed or mobile.

FIG. 2 is a schematic diagram of an architecture example of acommunications system. As shown in FIG. 2, a network device in a radioaccess network RAN is a base station (for example, a gNB) with a CU/DUsplit architecture. The RAN may be connected to a core network (forexample, an LTE core network or a 5G core network). A CU and a DU may beunderstood as division of a base station from a logical functionperspective. The CU and the DU can be physically separated or physicallydeployed together. A function of the RAN is ended up on the CU. Aplurality of DUs can share one CU. One DU may also be connected to aplurality of CUs (not shown in the figure). The CU and the DU may beconnected by using an interface, for example, an F1 interface. The CUand the DU may be obtained through division based on protocol layers ofa wireless network. For example, functions of a packet data convergenceprotocol (PDCP) layer and a radio resource control (RRC) layer are setin the CU, and functions of a radio link control (RLC) layer, a mediaaccess control (MAC) layer, a physical layer, and the like are set inthe DU. It may be understood that, that processing functions of the CUand the DU are divided based on these protocol layers is merely anexample, and the processing functions may alternatively be divided inanother manner. For example, functions of more protocol layers may bedistributed to the CU or the DU. For example, some processing functionsof the protocol layers may be further distributed to the CU or the DU.In a design, some functions of the RLC layer and functions of a protocollayer above the RLC layer are set in the CU, and remaining functions ofthe RLC layer and functions of a protocol layer below the RLC layer areset in the DU. In another design, functions of the CU or the DU mayalternatively be divided based on a service type or another systemrequirement. For example, division is performed based on a delay, afunction whose processing time needs to meet a delay requirement is setin the DU, and a function whose processing time does not need to meetthe delay requirement is set in the CU. The network architecture shownin FIG. 2 may be applied to a 5G communications system, and the networkarchitecture may alternatively share one or more components or resourceswith an LTE system. In another design, the CU may alternatively have oneor more functions of the core network. One or more CUs may be set in acentralized manner or a separated manner. For example, the CU may be seton a network side for centralized management; and the DU may have aplurality of radio frequency functions, or a radio frequency functionmay be remotely set.

The function of the CU may be implemented by one entity. Alternatively,a control plane (CP) and a user plane (UP) may be further separated. Tobe specific, the control plane of the CU (CU-CP) and the user plane ofthe CU (CU-UP) may be implemented by different functional entities, andthe CU-CP and the CU-UP may be coupled to the DU to jointly implement afunction of the base station.

In this application, nouns “network” and “system” are usuallyinterchangeably used, and an “apparatus” and a “device” are also usuallyinterchangeably used. However, meanings of the nouns can be understoodby a person skilled in the art. A “communications apparatus” may be thenetwork device (for example, the base station, the DU, or the CU) or theterminal in FIG. 1 and FIG. 2, or a component (for example, anintegrated circuit or a chip) of the network device or the terminal, oranother communications module.

FIG. 3 is a schematic diagram of an SRS carrier switching solution. Asshown in FIG. 3, two orthogonal frequency division multiplexing (OFDM)symbols are required for a UE RF, a CC 2 is a switching-to UL CC, and aCC 1 is a switching-from UL CC. When UE switches from the CC 1 to the CC2 to send an SRS, the UE cannot send a physical uplink shared channel(PUSCH) on symbols 11 to 13 in a subframe N and symbols 0 and 1 in asubframe N+1, where these symbols correspond to the CC 1.

For ease of description, terms in an LTE system are used as examples inthis application. It may be understood that other terms may also be usedin other systems. The following describes some terms in thisapplication, to facilitate understanding of a person skilled in the art.

A cell may refer to a coverage area of a base station and/or a basestation subsystem serving the coverage area. For example, a coveragearea of an eNB may be a macro cell, a micro cell, a pico cell, or a cellof another type. The macro cell may cover a relatively largegeographical area, and the micro cell may cover a relatively smallgeographical area, or the like. The base station can support one or morecells. For a terminal, a cell serving the terminal may include onedownlink carrier and one uplink carrier (for example, the LTE network).After an SUL resource is introduced, the cell serving the terminal mayalternatively include one downlink carrier and a plurality of uplinkcarriers. For example, in 5G communication, a cell may include onedownlink carrier and two uplink carriers.

The SUL resource indicates that only an uplink resource is used fortransmission in a current communications standard. For example, for acarrier, only an uplink resource is used for transmission. For example,in the 5th generation (5G) mobile communications system also referred toas an NR communications system, a carrier A is used for only NR uplinktransmission and is not used for downlink transmission. Alternatively,the carrier A is used for uplink transmission in an LTE communicationssystem and is not used for downlink transmission in NR. In this case,the carrier A is the SUL resource.

An SUL cell is sometimes referred to as a cell including an SUL, andrefers to a cell including the SUL resource.

A carrier is a radio wave at a specific frequency and is anelectromagnetic wave that can be modulated in aspects such as afrequency, amplitude modulation, or a phase to transmit language, music,an image, or another signal.

The uplink resource may be understood as a carrier (including a carrierin a non-CA scenario and a carrier in a CA scenario). In other words,the uplink resource may be a part that is of the carrier and that isused for uplink transmission. Alternatively, the uplink resource mayalso be understood as a part that is of a cell (including a cell in a CAscenario and a cell in a non-CA scenario) and that is used for uplinktransmission. In other words, the uplink resource may be a part that isof the cell and that is used for uplink transmission. The CC in the CAscenario may be a primary CC or a secondary CC, and the cell in the CAscenario may be a primary cell (PCell) or a secondary cell (SCell). Theuplink resource may alternatively be referred to as the uplink carrier.Correspondingly, a part that is of the carrier or the cell and that isused for the downlink transmission may be understood as a downlinkresource or a downlink carrier. For example, in an FDD system, afrequency resource used for uplink transmission on a carrier may beunderstood as the uplink resource or the uplink carrier, and a frequencyresource used for downlink transmission on a carrier may be understoodas the downlink resource or the downlink carrier. For another example,in a TDD system, a time domain resource used for uplink transmission ona carrier may be understood as the uplink resource or the uplinkcarrier, and a time domain resource used for downlink transmission on acarrier may be understood as the downlink resource or the downlinkcarrier.

FIG. 4 is a flowchart of a wireless communication method according to anembodiment of this application. The method may be applied to thenetworks shown in FIG. 1 and FIG. 2.

Part 101. A network device sends configuration information to UE.

The configuration information includes information about at least twouplink carriers. For example, the configuration information includesfirst uplink carrier information and second uplink carrier information.The first uplink carrier information is used to indicate that a firstuplink carrier is a switching-from uplink carrier for an SRS carrierswitching, and the second uplink carrier information is used to indicatethat a second uplink carrier is a switching-to uplink carrier for theSRS carrier switching. At least one of the first uplink carrier and thesecond uplink carrier belongs to a cell including an SUL resource.

Optionally, the configuration information further includes configurationinformation of an SRS of the UE on the second uplink carrier, and isused to configure time domain information, frequency domain information,and code domain information for UE SRS transmission.

The configuration information may be dedicated instruction information,or may be carried in radio resource control (RRC) information (forexample, RRC connection setup signaling, RRC connection reestablishmentsignaling, or RRC connection reconfiguration signaling) or downlinkcontrol information (DCI).

A cell to which the SRS switching-from uplink carrier belongs is aswitching-from cell, and a cell to which the SRS switching-to uplinkcarrier belongs is a switching-to cell. As shown in FIG. 5, a cell 1 isan SUL cell, and the cell 1 includes a 1.8 G SUL carrier and a 3.5 Guplink (UL) carrier. If the cell 1 is a switching-from cell, and the 3.5G UL carrier is an SRS switching-from uplink carrier, the first uplinkcarrier information may include information used to indicate cell 1 andthe 3.5 G UL carrier. In other words, the first uplink carrierinformation includes information used to indicate a switching-from celland information used to indicate a switching-from carrier. Similarly, asshown in FIG. 6, if a cell 1 is a switching-to cell, and a 3.5 G ULcarrier is an SRS switching-to uplink carrier, the second uplink carrierinformation may include information used to indicate cell 1 and the 3.5G UL carrier. In other words, the second uplink carrier informationincludes information used to indicate the switching-to cell andinformation used to indicate the switching-to carrier.

Optionally, at least one of the first uplink carrier information and thesecond uplink carrier information includes a cell identifier and anuplink carrier identifier. The cell identifier is used to identify acell, for example, a cell index, a secondary cell index (SCellIndex), orother information that may be used to identify a cell. The uplinkcarrier identifier is used to identify a carrier, for example, acomponent carrier index (CC index), an uplink index (UL index), asecondary cell SUL index (SCellSULIndex), or other information that canbe used to identify a carrier. Herein, SCellSULIndex is an identifier ofan uplink carrier. Representation manners and names of the cellidentifier and the uplink carrier identifier are not limited in thisapplication. For example, in the example shown in FIG. 5, theinformation used to indicate the switching-from cell may be the cellidentifier, for example, the cell index or the secondary cell index. Twouplink carriers, one UL carrier, and one SUL carrier are in aswitching-from cell 1. The information identifying the switching-fromcarrier may be a carrier identifier, to indicate whether theswitching-from carrier is the 1.8 G SUL carrier or the 3.5 G UL carrier.In another example, the carrier identifier may indicate whether theswitching-from carrier is the UL carrier or the SUL carrier. If it isindicated that the switching-from carrier is the UL carrier, it may belearned that the switching-from carrier is the 3.5 G UL carrier. If theswitching-from carrier is the SUL carrier, it may be learned that theswitching-from carrier is the 1.8 G SUL carrier. This is similar to theexample in FIG. 6, and details are not described again.

In the following description, these different expressions are sometimesinterchangeably used, and are used to indicate the cell identifier orthe uplink carrier identifier.

The cell identifier and the uplink carrier identifier may be used toindicate the SRS switching-from uplink carrier and/or the SRSswitching-to uplink carrier.

In the example shown in FIG. 5, the cell 1 is a switching-from cell, andcell 1 includes two uplink carriers: a 1.8 G SUL carrier and a 3.5 G ULcarrier. The 3.5 G UL carrier is an SRS switching-from uplink carrier.The first uplink carrier information includes an identifier of cell 1and an identifier of the 3.5 G UL carrier. For example, two informationelement: SCellIndex and SCellSULIndex may be used in the first uplinkcarrier information to indicate the SRS switching-from uplink carrierfor an SRS carrier switching. Cell 2 is a switching-to cell, and cell 2includes a 3.5 G UL carrier. The second uplink carrier information mayinclude an identifier of cell 2. For example, SCellIndex may be used inthe second uplink carrier information to indicate the SRS switching-touplink carrier for the SRS carrier switching.

In the example shown in FIG. 6, cell 1 is a switching-to cell, and cell1 includes two uplink carriers: a 1.8 G SUL carrier and the 3.5 G ULcarrier. The 3.5 G UL carrier is an SRS switching-to uplink carrier foran SRS carrier switching. The second uplink carrier information includesan identifier of cell 1 and an identifier of the 3.5 G UL carrier. Forexample, two information elements: SCellIndex and SCellSULIndex may becomprised in the second uplink carrier information to indicate the SRSswitching-to uplink carrier. A cell 2 is the switching-from cell, andcell 2 includes a 3.5 G UL carrier. Therefore, the first uplink carrierinformation may include an identifier of the cell 2. For example,SCellIndex may be used in the first uplink carrier information toindicate the SRS switching-from uplink carrier.

In an example shown in FIG. 7, cell 2 is the switching-from cell, andcell 2 includes two uplink carriers: a 1.8 G SUL carrier and a 3.5 G ULcarrier. The 3.5 G UL carrier is the SRS switching-from uplink carrierfor the SRS carrier switching. Therefore, the first uplink carrierinformation includes an identifier of cell 2 and an identifier of the3.5 G UL carrier. For example, two information elements: SCellIndex andSCellSULIndex may be comprised in the first uplink carrier informationto indicate the SRS switching-from uplink carrier. Similarly, cell 1 isa switching-to carrier, and cell 1 includes two uplink carriers: a 1.8 GSUL carrier and a 3.5 G UL carrier. The 1.8 G SUL carrier is an SRSswitching-to uplink carrier for the SRS carrier switching. Therefore,the second uplink carrier information includes an identifier of cell 1and an identifier of the 1.8 G SUL carrier. For example, two informationelements: SCellIndex and SCellSULIndex may be used in the second uplinkcarrier information to indicate the SRS switching-to uplink carrier.

For example, as shown in Code 1, if the switching-from UL CC indicatedby an SCellIndex belongs to an SUL cell, an SCellSULIndex field needs tobe additionally used to indicate the switching-from UL CC. If theswitching-to UL CC is an SUL cell, and an SRS needs to be transmitted onan SUL carrier and a non-SUL carrier, two switching-from UL CCs need tobe configured.

Optionally, the second uplink carrier information of the second uplinkcarrier may implicitly indicate the SRS switching-to uplink carrier byusing SCellIndex and resource configuration. For example, in thepseudocode 1, information elements: SCellIndex andradioResourceConfigDedicatedSCell jointly indicate that the seconduplink carrier is the 3.5 G UL carrier, andradioResourceConfigDedicatedSCell includes SRS configuration informationand some other UE-level configuration information on the 3.5 G ULcarrier. The information elements SCellIndex andSULradioResourceConfigDedicatedSCell jointly indicate that the seconduplink carrier is the 1.8 G SUL carrier, andSULradioResourceConfigDedicatedSCell includes SRS configurationinformation and some other UE-level configuration information on the 1.8G SUL.

Code 1: SCellToAddMod-r10 ::= SEQUENCE{ sCellIndex-r10SCellIndex-r10, //switch-to CC cellIdentification-r10 SEQUENCE{physCellId-r10 PhysCellId, dl-CarrierFreq-r10 ARFCN-ValueEUTRA }OPTIONAL, -- Cond SCellAdd radioResourceConfigCommonSCell-r10RadioResourceConfigCommonSCell-r10 OPTIONAL, -- Cond SCellAddradioResourceConfigDedicatedSCell-r10RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 ...,[[ dl-CarrierFreq-v1090 ARFCN-ValueEUTRA-v9e0 OPTIONAL -- CondEARFCN-max ]], [[ antennaInfoDedicatedSCell-v10ioAntennaInfoDedicated-v10i0 OPTIONAL -- Need ON ]], [[srs-SwitchFromServCellIndex-r14 INTEGER (0.. 15) OPTIONAL -- Need ON//switch-from CC SCellSULIndex SCellSULIndex(1bit(0,1)/2bit(0,1,2,3))optional//UL_CC_index ]] SULradioResourceConfigCommonSCell-r10RadioResourceConfigCommonSCell-r10 OPTIONAL, -- Cond SCellAddSULradioResourceConfigDedicatedSCell-r10RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 [[srs-SwitchFromServCellIndex-r14 INTEGER (0.. 15) OPTIONAL -- Need ON//switch-from CC SCellSULIndex SCellSULIndex(1bit(0,1)/2bit(0,1,2,3))optional //UL_CC_index ]]  }

Optionally, if a cell to which the second uplink carrier belongs is acell including an SUL, the second uplink carrier is a non-SUL carrier.

The non-SUL carrier is an uplink carrier in a 5G system, for example, anNR dedicated UL carrier.

In this embodiment, the non-SUL carrier in the cell including the SULmay be defined as the second uplink carrier in a predefined manner of aprotocol. In other words, the non-SUL carrier in the cell including theSUL is the SRS switching-to uplink carrier by default. For example, ifan SCell is the SUL cell, the SCell includes a TDD carrier and an SULcarrier, and downlink carriers of the SUL carrier and the TDD carrierare at different frequencies, and do not have channel reciprocity. Foran SUL cell in which there is no PUSCH/physical uplink control channel(PUCCH) transmission, a downlink channel condition of the SUL cellcannot be obtained by using an SRS configured on the SUL carrier.Therefore, when neither of two UL CCs of the SUL cell is configured witha PUSCH/PUCCH, it may be predefined in the protocol that theswitching-to UL CC is a non-SUL carrier, for example, the 3.5 G ULcarrier in cell 1 in FIG. 6.

Optionally, if a serving cell to which the first uplink carrier belongsis the cell including the SUL, the first uplink carrier is a non-PUCCHcarrier. In other words, no uplink carrier for the PUCCH transmission isconfigured in the cell including the SUL carrier.

In LTE Rel-14, the first uplink carrier is defined as an uplink carrierthat is in a TDD serving cell and that is not configured for thePUSCH/PUCCH transmission.

In this embodiment, the non-PUCCH carrier in the cell including the SULcarrier is predefined (for example, by using a protocol specification,through pre-negotiation, or through pre-configuration) as the firstuplink carrier. In other words, the non-PUCCH carrier in the cellincluding the SUL carrier is the SRS switching-from uplink carrier bydefault. For example, if a cell to which the switching-from UL CCbelongs is the SUL cell, because the SUL cell includes two uplinkcarriers, one uplink carrier (for example, the non-PUCCH carrier or acarrier for latest uplink transmission) in the SUL cell is predefined asthe first uplink carrier.

Further, because a resource of the switching-from UL CC (for example, aUL RF capability) is required for an SRS on the switching-to UL CC, ifthe SUL cell is used as a primary cell, RRC signaling is configured witha PUCCH carrier. To avoid an impact on the PUCCH, it may be predefinedthat the switching-from UL CC is the non-PUCCH carrier (for example, byusing a protocol agreement, through pre-configuration, or throughpre-agreement), for example, the 3.5 G UL carrier in the cell 1 shown inFIG. 5. If the SUL cell is used as a secondary cell, it may bepredefined in a protocol that the switching-from UL CC is an uplinkcarrier for latest PUSCH transmission.

For example, as shown in Code 2, because it is predefined that thenon-PUCCH carrier in the cell including the SUL carrier is the firstuplink carrier, a cell identifier (e.g. sCellIndex-r10) is configured inthe configuration information.

Code 2: SCellToAddMod-r10 ::= SEQUENCE{ sCellIndex-r10 SCellIndex-r10,(if SCell is a switching-to UL CC) cellIdentification-r10 SEQUENCE{physCellId-r10 PhysCellId, dl-CarrierFreq-r10 RFCN-ValueEUTRA }OPTIONAL, -- Cond SCellAdd radioResourceConfigCommonSCell-r10RadioResourceConfigCommonSCell-r10 OPTIONAL, -- Cond SCellAddradioResourceConfigDedicatedSCell-r10RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 ...,[[ dl-CarrierFreq-v1090 ARFCN-ValueEUTRA-v9e0 OPTIONAL -- CondEARFCN-max ]], [[ antennaInfoDedicatedSCell-v10ioAntennaInfoDedicated-v10i0 OPTIONAL -- Need ON ]], [[srs-SwitchFromServCellIndex-r14 INTEGER (0... 15) OPTIONAL -- Need ON(config a switching-from UL CC) ]] }

Optionally, if the UE is configured with one SUL cell, and the UE hasonly one set of uplink radio frequencies (UL RF), in other words, the UEis configured with an uplink carrier used for the PUSCH transmission,the switching-from UL CC is an uplink carrier configured with the PUSCHtransmission. Therefore, no switching-from UL CC needs to beadditionally specified in the configuration information. As shown inFIG. 8, a cell of the UE includes a 3.5 G UL carrier and a 1.8 G SULcarrier. If the 1.8 G SUL carrier is configured to transmit the PUSCH,the 1.8 G SUL carrier is the switching-from UL CC.

Optionally, the at least one of the first uplink carrier information andthe second uplink carrier information is a new carrier indicator field(NCIF) identifier. It may be understood that the NCIF identifier is usedto indicate the first uplink carrier and/or the second uplink carrier,and may also have other names, for example, a carrier indicator fieldCIF and a new radio carrier indicator field NR CIF. This is not limitedin this application.

In this embodiment, the SUL cell may be configured with a plurality ofNCIF identifiers, and each NCIF identifier corresponds to one 2-tuple(SCellIndex, ULCCindex). Herein, SCellIndex is a cell identifier, andULCCindex is an uplink carrier identifier. The switching-to UL CC or theswitching-from UL CC may be indicated by using the NCIF identifier, theNCIF identifier may be carried in an NCIF field of the DCI, and the NCIFfield may be multiplexed with a carrier indicator field (CIF). A personskilled in the art may also set another identifier to indicate the firstuplink carrier and/or the second uplink carrier, and the identifier isnot limited to the NCIF identifier.

As shown in FIG. 9, an NCIF 0 indicates a 1.8 G SUL carrier in a cell 2,an NCIF 1 indicates a 3.5 G UL carrier in the cell 2, and an NCIF 2indicates a 3.5 G UL carrier in a cell 1. When there is another cell andanother uplink carrier, more NCIF identifiers may be set to identifydifferent uplink carriers in different cells. As shown in Code 3, theNCIF identifiers may be used to indicate a corresponding switching-fromUL CC and a corresponding switching-to UL CC.

Code 3:  SCellToAddMod-r10 ::= SEQUENCE{ sCellIndex-r10 NCIF,//switch-to UL CC cellIdentification-r10 SEQUENCE{ physCellId-r10PhysCellId, dl-CarrierFreq-r10 ARFCN-ValueEUTRA } OPTIONAL, -- CondSCellAdd radioResourceConfigCommonSCell-r10RadioResourceConfigCommonSCell-r10 OPTIONAL, -- Cond SCellAddradioResourceConfigDedicatedSCell-r10RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 ...,[[ dl-CarrierFreq-v1090 ARFCN-ValueEUTRA-v9e0 OPTIONAL -- CondEARFCN-max ]], [[ antennaInfoDedicatedSCell-v10i0AntennaInfoDedicated-v10i0 OPTIONAL -- Need ON ]], [[srs-SwitchFromServCellIndex-r14 NCIF OPTIONAL -- Need ON //switch-fromUL CC ]]  }

Optionally, when UE-level PUSCH configuration information, UE-levelPUCCH configuration information, and UE-level SRS configurationinformation are configured by using RRC signaling, the RRC signalingfurther includes the NCIF identifier.

For example, the RRC signaling may be, for example, RRC connectionconfiguration (connectionsetup) signaling, the RRC connectionreconfiguration (connectionreconfiguration) signaling, or the RRCconnection reestablishment (connectionreestablishment) signaling. TheRRC signaling may include at least one of radio resource configurationinformation (for example, RadiorResourceConfigDedicated) and SUL radioresource configuration information (for example,SULRadioResourceConfigDedicated). If the RRC signaling includes both theradio resource configuration information and the SUL radio resourceconfiguration information, the radio resource configuration informationis associated with at least one NCIF identifier (for example, NCIF 1),and the SUL radio resource configuration information is associated withat least one NCIF identifier (for example, NCIF 2). An associationmanner is not limited. For example, the identifier NCIF 1 andRadioResourceConfigDedicated may be two information elements in the RRCsignaling, and the NCIF 1 may also be carried inRadioResourceConfigDedicated information. The identifier NCIF 2 andSULRadioResourceConfigDedicated may be two information elements in theRRC signaling, and the identifier NCIF 2 may also be carried in SULRadioResourceConfigDedicated information.

The radio resource configuration information may include non-SULconfiguration information (RadioResourceConfigULDedicated). Optionally,the radio resource configuration information may further include DLUE-level configuration information. The SUL radio resource configurationinformation may include SUL configuration information(RadioResourceConfigULDedicated), or may include other configurationinformation. In this application, names of messages and names ofinformation elements are merely examples, and other names may also beused. This is not limited in this application.

As shown in Code 4, in RRCconnectionsetup signaling configuration,RadioResourceConfigDedicated is associated with the identifier NCIF 1,and SULRadioResourceConfigDedicated is associated with the identifierNCIF 2.

Code 4: RRCConnectionSetup-r8-IEs ::= SEQUENCE{ sCellIndex NCIF1OPTIONAL radioResourceConfigDedicated  RadioResourceConfigDedicated,sCellIndex NCIF2 OPTIONAL SULRadioResourceConfigDedicatedRadioResourceConfigDedicated, OPTIONAL nonCriticalExtensionRRCConnectionSetup-v8a0-IEs OPTIONAL }

Optionally, as shown in Code 5, in radioresourceconfigdedicatedconfiguration, physical configuration information(physicalconfigdedicated) may be associated with the identifier NCIF 1,and SUL physical configuration information (SULphysicalconfigdedicated)is associated with the identifier NCIF 2. An association manner is notlimited. An NCIF identifier may be parallel withphysicalconfigdedicated, or may be carried in physicalconfigdedicated. Aspecific manner of configuring the NCIF identifier is not limited by theforegoing examples. Optionally, physicalconfigdedicated may includenon-SUL configuration information (physicalconfigULdedicated), andoptionally, may further include non-SUL UE-level configurationinformation and DL UE-level configuration information. Herein,physicalSULconfigdedicated includes SUL configuration information. Aspecific name of an information element is not limited to the foregoingmanner.

Herein, physicalconfigdedicated includes UE-level PUSCH configurationinformation, UE-level PUCCH configuration information, UE-level PDCCHconfiguration information, and UE-level SRS configuration information onthe non-SUL carrier; and SULphysicalconfigdedicated includes UE-levelPUSCH configuration information, UE-level SRS configuration information,and UE-level PUCCH configuration information on the SUL. Optionally,physicalconfigdedicated may include the non-SUL configurationinformation, and physicalconfigdedicated may be renamed asphysicalconfigULdedicated. Optionally, physicalconfigdedicated mayfurther include non-SUL UE-level configuration information and the DLUE-level configuration information. Herein, SULphysicalconfigULdedicatedincludes the SUL configuration information. A specific name of aninformation element is not limited to the foregoing manner.

Code 5:  RadioResourceConfigDedicated::= SEQUENCE{ ..., sCellIndex NCIF1 OPTIONAL physicalConfigDedicatedPhysicalConfigDedicated OPTIONAL, -- Need ON sCellIndex  NCIF2 OPTIONALSULphysicalConfigDedicated PhysicalConfigDedicated OPTIONAL, -- Need ONdynamicScheduling True/False  OPTIONAL ...,  }

Optionally, the NCIF identifier includes a cell identifier and/or anuplink carrier identifier. For example, when a serving cell is an SULcell, the NCIF identifier is equivalent to a cell identifier and anuplink carrier identifier; or when the serving cell is a cell thatincludes only one uplink carrier and one downlink carrier, the NCIFidentifier is equivalent to a cell identifier.

In this embodiment, the NCIF identifier may be an identifier generatedbased on the cell identifier and the uplink carrier identifier. Forexample, SCellIndex and SCellSULIndex may be used as the NCIFidentifier. Alternatively, the NCIF identifier may be an identifiergenerated based on the cell identifier. It may be understood thatanother part may be added into an NCIF to form another structure. Thisdoes not affect functions of the NCIF in the solutions of thisapplication.

It should be noted that a manner in which one SUL cell including aplurality of NCIF identifiers is configured by using RRC signaling isnot limited to the foregoing examples.

Optionally, an example in which one SUL cell including a plurality ofNCIF identifiers is configured by using RRC signaling is shown in FIG.10. A 3.5 G downlink (DL) carrier and a 3.5 G uplink (UL) carrier areassociated with an NCIF 0; and a 1.8 G SUL carrier is associated with anNCIF 1, or the 3.5 G DL carrier and the 1.8 G SUL carrier are associatedwith the NCIF 1. Therefore, the first carrier information and the secondcarrier information may be represented by using the NCIF identifier. IfRRC configuration signaling includes both configuration information of aUL bandwidth BWP 1 on a UL CC and configuration information of a UL BWP1 on an SUL CC or the RRC configuration signaling explicitly indicatingto activate the UL CC and the SUL CC, a base station gNB may dynamicallyschedule PUSCH transmission on the UL CC and the SUL CC, or the RRCsignaling is used to explicitly configure the gNB to dynamicallyschedule the PUSCH transmission on the UL CC and the SUL CC. Uplinkscheduling grant information includes an NCIF value, and is used toindicate whether a scheduled PUSCH is transmitted on the 1.8 G SULcarrier or on the 3.5 G UL carrier. When the SUL cell includes aplurality of SUL carriers, a value of the NCIF identifier configured forthe SUL cell is equal to 1 plus a quantity of SUL carriers.

A bandwidth may be a segment of contiguous resources in frequencydomain. The bandwidth may be sometimes referred to as a bandwidth part(BWP), a carrier bandwidth part, a subband bandwidth, a narrowbandbandwidth, or another name. The name is not limited in this application.For example, one BWP includes K (K>0) contiguous subcarriers.Alternatively, one BWP is a frequency domain resource in which N (N>0)non-overlapping contiguous resource blocks (RBs) are located, and asubcarrier spacing of the RB may be 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240kHz, 480 kHz, or another value. Alternatively, one BWP is a frequencydomain resource in which M (M>0) non-overlapping contiguous resourceblock groups (RBGs) are located. One RBG includes P (P>0) contiguousRBs, and a subcarrier spacing of the RB may be 15 kHz, 30 kHz, 60 kHz,120 kHz, 240 kHz, 480 kHz, or another value.

Part 102. The UE receives the configuration information, and determinesthe SRS switching-from uplink carrier and the SRS switching-to uplinkcarrier based on the configuration information.

For example, the UE may determine the SRS switching-from uplink carrierbased on the first uplink carrier information, and determines the SRSswitching-to uplink carrier based on the second uplink carrierinformation.

For example, after the configuration information is parsed, the UEdetermines the SRS switching-from uplink carrier based on the firstuplink carrier information, and determines the SRS switching-to uplinkcarrier based on the second uplink carrier information. As shown in FIG.5, if the first uplink carrier information includes the identifier ofcell 1 and the identifier of the 3.5 G UL carrier, the SRSswitching-from uplink carrier is the 3.5 G UL carrier in cell 1. Asshown in FIG. 6, if the second uplink carrier information includes theidentifier of cell 1 and the identifier of the 3.5 G UL carrier, the SRSswitching-to uplink carrier is the 3.5 G UL carrier in cell 1. As shownin FIG. 9, if the first uplink carrier information includes the NCIF 1,the SRS switching-from uplink carrier is the 3.5 G UL carrier in thecell 2.

According to an SRS transmission method provided in this embodiment ofthis application, the network device sends, to the UE, the configurationinformation that includes the first uplink carrier information and thesecond uplink carrier information. The UE determines the SRSswitching-from uplink carrier based on the first uplink carrierinformation, and determines the SRS switching-to uplink carrier based onthe second uplink carrier information. When the SUL cell is used as theswitching-from UL CC, whether the RF capability of the SUL or the RFcapability of the non-SUL is used may be determined. When the SUL cellis used as the switching-to UL CC, whether to transmit the SRS on theSUL carrier or the non-SUL carrier may be determined. In this way, thereliability of the SRS transmission is ensured.

FIG. 11 is a flowchart of a wireless communication method according toanother embodiment of this application. Based on the embodiment shown inFIG. 4, the method further includes the following:

Part 201. A network device sends downlink control information DCI to UE.

For example, the DCI includes aperiodic A-SRS trigger indicationinformation and an uplink carrier identifier. The uplink carrieridentifier is used to indicate a second uplink carrier.

In this embodiment, if the UE is configured with only one serving celland the serving cell is an SUL cell, or an SRS switching-to uplinkcarrier of the UE is an SUL cell, when a configured SRS is an A-SRS, itneeds to be further indicate that an A-SRS triggered by DL-DCI orgroup-level DCI on the SUL cell is an A-SRS on which uplink carrier.Therefore, an uplink carrier on which the A-SRS is triggered may beindicated by using the DCI.

Optionally, configuration information includes an A-SRS identifier, andthe A-SRS identifier is associated with the second uplink carrier.

In this embodiment, A-SRS resources on an SUL carrier and a non-SULcarrier in a cell may be uniformly numbered, and each A-SRS identifier(index) is associated with one A-SRS on one UL CC. For example, A-SRSresources in FIG. 7 are uniformly numbered, and an A-SRS index 1 isassociated with the 3.5 G UL carrier in the cell 1, an A-SRS index 2 isassociated with the 1.8 G SUL carrier in the cell 1, an A-SRS index 3 isassociated with the 3.5 G UL carrier in the cell 2, and an A-SRS index 4is associated with the 1.8 G SUL carrier in the cell 2. A correspondinguplink carrier may be determined based on the A-SRS index. One uplinkcarrier may include a plurality of A-SRS resources, or the foregoingmanner may be used to uniformly number the A-SRS resources.

Optionally, a 1-bit or multi-bit SUL CIF field may be added to eachinformation block of the group-level DCI, and the SUL CIF field is usedto indicate the second uplink carrier.

In a design, a quantity of bits required in each information block isrelated to a quantity of uplink carriers included in the SUL cell. It isassumed that N bits are required, and the quantity of uplink carriers isM. In this case, N=log₂M.

Optionally, the DCI carries the A-SRS trigger indication information,and the uplink carrier information may be predefined as a non-SULcarrier.

Optionally, an implementation of determining the SRS switching-to uplinkcarrier based on the configuration information in Part 102 includes thefollowing:

Part 202. The UE receives the DCI, and determines an A-SRS switching-touplink carrier based on the A-SRS trigger indication information and theuplink carrier identifier information in the DCI, and the configurationinformation received in Part 102.

In this embodiment, after second uplink carrier information isconfigured in the configuration information, if the SRS is the A-SRS,the SRS switching-to uplink carrier needs to be determined based on thesecond uplink carrier information, the A-SRS trigger indicationinformation, and the uplink carrier identifier information.

Optionally, when the configured SRS is a semi-persistent SPS-SRS, referto the method in FIG. 11.

According to the SRS transmission method provided in this embodiment ofthis application, the network device sends, to the UE, the DCI thatcarries the A-SRS trigger indication information and/or the uplinkcarrier identifier information. The UE determines the SRS switching-touplink carrier based on the second uplink carrier information, the A-SRStrigger indication information, and the uplink carrier identifierinformation. In a special SRS scenario, the SRS switching-from uplinkcarrier and the SRS switching-to uplink carrier may also be determined.Therefore, the method may be applied in more scenarios.

Optionally, based on any embodiment in FIG. 4 to FIG. 11, theconfiguration information is further used to indicate a location of anuplink carrier in an information block of UE-group-level DCI, the uplinkcarrier is not used to transmit a PUSCH/PUCCH, and the information blockof the UE-group-level DCI includes at least one of SRS power controlinformation, A-SRS trigger indication information, and uplink carrieridentifier information of the uplink carrier that is not used totransmit the PUSCH/PUCCH.

In this embodiment, if the UE is configured with a maximum of N (N is apositive integer, for example, N is 4 or another value) uplink carriersthat are not used to transmit the PUSCH/PUCCH, the UE group-level DCI(group DCI) includes a plurality of information blocks, and eachinformation block includes at least one of the SRS power controlinformation, the A-SRS trigger indication information, and the uplinkcarrier identifier information of the uplink carrier that is not used totransmit the PUSCH/PUCCH. The configuration information indicates thelocation of the uplink carrier in the information block of theUE-group-level DCI, that is, the configuration information indicates thesecond uplink carrier, where the uplink carrier is not used to transmitthe PUSCH/PUCCH. For example, the configuration information indicatesthe corresponding location of the uplink carrier in the informationblock of the UE-group-level DCI, where the uplink carrier is not used totransmit the PUSCH/PUCCH. To be specific, the information block includesat least one of the second uplink carrier identifier information, powercontrol information, or the A-SRS trigger indication information.

For example, when the UE is configured with a maximum of fourPUSCH/PUCCH-less carriers, RRC signaling carries a dedicated physicalresource configuration information element of an SCell. The dedicatedphysical resource configuration information element of the SCellincludes a transmit power control (TPC) configuration informationelement of typeB, and the configuration information element is used toconfigure a corresponding block location of the SCell in the group-levelDCI. One UE is configured with a maximum of four blocks in thegroup-level DCI. When a periodic P-SRS needs to be transmitted on thePUSCH/PUCCH-less carrier, group-level DCI signaling includes only TPCsignaling. When the A-SRS is configured on the PUSCH/PUCCH-less carrier,the group-level DCI signaling includes at least one of the TPCsignaling, the A-SRS trigger indication information, or the uplinkcarrier indication information. When the SPS-SRS is configured on thePUSCH/PUCCH-less carrier, the group-level DCI signaling includes atleast one of the TPC signaling, SPS-SRS activation/deactivationsignaling, or the uplink carrier indication information.

As shown in Code 6, the TPC configuration information element of typeBis configured in PhysicalConfigDedicated.

Code 6:  PhysicalConfigDedicatedSCell::= SEQUENCE{ ...,typeB-SRS-TPC-PDCCH-Config SRS-TPC-PDCCH-Config OPTIONAL, -- Need ON <=4SRS-only CCs ...,  }

Optionally, the configuration information further includes an index of acarrier group to which the uplink carrier that is not used to transmitthe PUSCH/PUCCH belongs and an index of a carrier in the group.

In this embodiment, if the UE is configured to include more than N (N isa positive integer, for example, N=4 or other values) uplink carriersthat are not used to transmit the PUSCH/PUCCH, and the more than Nuplink carriers that are not used to transmit the PUSCH/PUCCH areconfigured into M groups, the configuration information further includesan index of a group to which the uplink carrier that is not used totransmit the PUSCH/PUCCH belongs and the uplink carrier identifier, andthe second uplink carrier may be determined based on the index of thegroup and the uplink carrier identifier.

For example, when the UE is configured with more than fourPUSCH/PUCCH-less carriers, the RRC signaling carries a dedicatedphysical resource configuration information element. The dedicatedphysical resource configuration information element includes a TPCconfiguration information element of typeA, and the configurationinformation element of typeA is used to configure an index of a carriergroup (CCSetIndex) to which the PUSCH/PUCCH-less carrier belongs and anindex of a carrier in the group (CCIndexInOneCcSet). The TPCconfiguration information element of typeA may include allPUSCH/PUCCH-less carrier information. When the P-SRS needs to betransmitted on the PUSCH/PUCCH-less carrier, an information block of thegroup-level DCI signaling includes the index of the carrier group andthe TPC signaling. When the A-SRS is configured on the PUSCH/PUCCH-lesscarrier, a block of the group-level DCI signaling includes the index ofthe carrier group and the TPC signaling, the A-SRS is triggered bydownlink DCI, and the downlink DCI includes uplink carrier indexindication information. When the SPS-SRS is configured on thePUSCH/PUCCH-less carrier, a block of the group-level DCI signalingincludes the index of the carrier group and the TPC signaling, SPS-SRSactivation/deactivation signaling is triggered by the downlink DCI or amedia access control (MAC) control element (CE). One UE corresponds toone block in the group-level DCI signaling. The index of the carriergroup in the block of the group-level DCI signaling is used to indicatea triggered carrier group, and a TPC field in the block indicates an SRSpower control command on a corresponding second uplink carrier.

As shown in Code 7, the TPC configuration information element of typeAis configured in physicalconfigdedicated.

Code 7: PhysicalConfigDedicated ::= SEQUENCE{ ..., [[typeA-SRS-TPC-PDCCH-Group SEQUENCE (SIZE (1..16)) OF SRS-TPC-PDCCH-Config OPTIONAL, -- Need ON each group contains at most 4SRS-only CCs(PUSCH/PUCCH less CCs) ..., } SRS-TPC-PDCCH-Config::= CHOICE{ release NULL, setup SEQUENCE{ srs-TPC-RNTI-r14 BIT STRING (SIZE (16)),startingBitOfFormat3B-r14 INTEGER (0..15), fieldTypeFormat3B-r14 INTEGER(1..4), TPC: 1/3 1bit; 2/4 2bits srs-CC-SetIndexlist-r14 SEQUENCE(SIZE(1..4)) OF SRS-CC-SetIndex-r14 OPTIONAL -- Cond Srs-Trigger-TypeA(if > 4 SRS-only CCs) } } SRS-CC-SetIndex-r14 ::= SEQUENCE{ccSetIndex-r14 INTEGER (0..3), ccIndexInOneCcSet-r14 INTEGER (0..3) }

Optionally, if SRS carrier switching is performed between the non-SULcarrier and the SUL carrier in the SUL cell, the switching-from UL CCmay be indicated during configuration of a UE-level SRS resource.

For example, the UE is configured to transmit the PUSCH and the SRS on a1.8 G SUL carrier, and to transmit only the SRS on a 3.5 G non-SULcarrier. A dedicated physical configuration information element of the3.5 G non-SUL carrier includes only UE-level dedicated SRS configurationinformation, and the dedicated SRS configuration information may includeA-SRS configuration information, P-SRS configuration information, andSPS-SRS configuration information. Therefore, in Code 8, a fieldsrs-swtichFromServCellIndex is an optional field. If the fieldsrs-swtichFromServCellIndex exists, a configured value is NCIF 2. Thismeans that SRS transmission on the 3.5 G non-SUL carrier needs to use aradio frequency module of the SUL. If the fieldsrs-swtichFromServCellIndex does not exist, the SRS transmission on the3.5 G non-SUL carrier does not need to use the radio frequency module ofthe SUL carrier.

An implementation of indicating the switching-from UL CC duringconfiguration of the UE-level SRS resource is shown in Code 8.

Code 8:  RadioResourceConfigDedicated::= SEQUENCE { ..., sCellIndex NCIF1 OPTIONAL physicalConfigDedicated PhysicalConfigDedicatedOPTIONAL, -- Need ON sCellIndex  NCIF2 OPTIONALSULphysicalConfigDedicated PhysicalConfigDedicated OPTIONAL, -- Need ONdynamicScheduling True/False  OPTIONAL ...,  }  PhysicalConfigDedicated::= SEQUENCE{ ..., soundingRS-UL-ConfigDedicatedSoundingRS-UL-ConfigDedicated OPTIONAL, -- Need ONsrs-SwitchFromServCellIndex-r14 INTEGER (0.. 16) OPTIONAL -- NeedON(NCIF2) ...,  }  SULPhysicalConfigDedicated ::= SEQUENCE{pucch-ConfigDedicated PUCCH-ConfigDedicated OPTIONAL, -- Need ONpusch-ConfigDedicated PUSCH-ConfigDedicated OPTIONAL, -- Need ONuplinkPowerControlDedicated UplinkPowerControlDedicated OPTIONAL, --Need ON tpc-PDCCH-ConfigPUCCH TPC-PDCCH-Config OPTIONAL, -- Need ONtpc-PDCCH-ConfigPUSCH TPC-PDCCH-Config OPTIONAL, -- Need ONcqi-ReportConfig CQI-ReportConfig OPTIONAL, -- Cond CQI-r8soundingRS-UL-ConfigDedicated SoundingRS-UL-ConfigDedicated OPTIONAL, --Need ON }

An embodiment of this application further provides a communicationsapparatus. The communications apparatus is configured to perform themethod according to any one of the foregoing embodiments. Thecommunications apparatus includes a necessary means to execute theforegoing method embodiments. The means may be implemented by usingsoftware and/or hardware. The communications apparatus may be thenetwork device or the terminal in FIG. 1 and FIG. 2.

FIG. 12 is a schematic structural diagram of a communications apparatus.The communications apparatus 20 may be the network device 20 in FIG. 1and FIG. 2. The network device may be configured to implement themethods described in the foregoing method embodiments. For details,refer to the descriptions in the foregoing method embodiments.

The communications apparatus 20 includes one or more processors 21. Theprocessor 21 may be a general-purpose processor, a dedicated processor,or the like. For example, the processor 21 may be a baseband processoror a central processing unit. The baseband processor may be configuredto process a communications protocol and communication data. The centralprocessing unit may be configured to: control the communicationsapparatus (for example, a base station, a baseband chip, a DU, or a CU),execute a software program, and process data of the software program.

In an optional design, the processor 21 may also include instruction(s)23. The instructions 23 may run on the processor 21, and cause thecommunications apparatus 20 to perform the methods described in theforegoing method embodiments.

In another possible design, the communications apparatus 20 may includea circuit. The circuit may implement the sending or receiving functionin the foregoing method embodiments.

Optionally, the communications apparatus 20 may include one or morememories 22. The memory 22 stores instruction(s) 24. The instructionsmay run on the processor 21, and cause the communications apparatus 20to perform the methods described in the foregoing method embodiments.Optionally, the memory may further store data. Optionally, the processormay alternatively store instruction(s) and/or data. The processor andthe memory may be separately disposed, or may be integrated together.

Optionally, the communications apparatus 20 may further include atransceiver 25 and/or an antenna 26. The processor 21 may be referred toas a processing unit, and controls the communications apparatus (aterminal or a base station). The transceiver 25 may be referred to as atransceiver unit, a transceiver machine, a transceiver circuit, atransceiver, or the like, and is configured to implement sending and/orreceiving functions of the communications apparatus by using the antenna26.

In a design, the communications apparatus (for example, an integratedcircuit, a wireless device, a circuit module, a network device, or aterminal device) may include a processor and a transceiver. For example,when the apparatus is configured to implement a function of the networkdevice, the transceiver may send the configuration information to the UEin FIG. 4, or the transceiver sends the DCI to the UE in FIG. 11. Forexample, when the apparatus is configured to implement a function of theterminal, in FIG. 4, the transceiver may receive the configurationinformation, and the processor determines, based on the configurationinformation, the SRS switching-from uplink carrier and the SRSswitching-to uplink carrier for the SRS carrier switching; or in FIG.11, the transceiver may receive the DCI, and the processor determinesthe switching-to uplink carrier of the A-SRS transmission based on thesecond uplink carrier information, the A-SRS trigger indicationinformation, and the uplink carrier identifier information.

The processor and the transceiver described in this application may beimplemented on an integrated circuit (IC), an analog IC, a radiofrequency integrated circuit RFIC, a hybrid signal IC, anapplication-specific integrated circuit (ASIC), a printed circuit board(PCB), an electronic device, or the like. The processor and thetransceiver may also be manufactured by using various IC technologies,for example, a complementary metal oxide semiconductor (CMOS), annMetal-oxide-semiconductor (NMOS), a positive channel metal oxidesemiconductor (PMOS), a bipolar junction transistor (Bipolar JunctionTransistor, BJT), a bipolar CMOS (BiCMOS), silicon germanium (SiGe), andgallium arsenide (GaAs).

The communications apparatus described in this application may be anindependent device or may be a part of a relatively large device. Forexample, the device may be as follows:

(1) an independent integrated circuit IC or a chip;

(2) a set of one or more ICs, where optionally, the IC set may alsoinclude a storage component configured to store data and/orinstruction(s);

(3) an ASIC, for example, a modem (MSM);

(4) a module that can be embedded in another device;

(5) a receiver, a cellular phone, a wireless device, a hand held device,a mobile unit, a network device, or the like; and

(6) another device, and the like.

FIG. 13 is a schematic structural diagram of a terminal. UE may beapplied to the system shown in FIG. 1. For ease of description, FIG. 13shows only main components of the terminal. As shown in FIG. 13, aterminal 10 includes a processor, a memory, a control circuit, anantenna, and an input/output apparatus. The processor is mainlyconfigured to: process a communications protocol and communication data,control the entire terminal, execute a software program, and processdata of the software program. The memory is mainly configured to storethe software program and the data. A radio frequency circuit is mainlyconfigured to: perform conversion between a baseband signal and a radiofrequency signal, and process the radio frequency signal. The antenna ismainly configured to receive and transmit a radio frequency signal in anelectromagnetic wave form. The input/output apparatus such as atouchscreen, a display screen, or a keyboard is mainly configured to:receive data entered by a user, and output data to the user.

After the user equipment is turned on, the processor may read a softwareprogram stored in a storage unit, explain and execute instruction(s) ofthe software program, and process data of the software program. Whendata needs to be sent in a wireless manner, the processor performsbaseband processing on the to-be-sent data, and outputs a basebandsignal to a radio frequency circuit. After the radio frequency circuitperforms radio frequency processing on the baseband signal, a radiofrequency signal is sent by using the antenna in an electromagnetic waveform. When data is sent to the user equipment, the radio frequencycircuit receives a radio frequency signal by using the antenna, convertsthe radio frequency signal into a baseband signal, and outputs thebaseband signal to the processor. The processor converts the basebandsignal into data and processes the data.

A person skilled in the art may understand that, for ease ofdescription, FIG. 13 shows only one memory and one processor. Actually,the terminal may include a plurality of processors and a plurality ofmemories. The memory may also be referred to as a storage medium, astorage device, or the like. This is not limited in this embodiment ofthis application.

In an optional implementation, the processor may include a basebandprocessor and a central processing unit. The baseband processor ismainly configured to process the communications protocol and thecommunication data. The central processing unit is mainly configured to:control the entire user equipment, execute the software program, andprocess the data of the software program. The processor in FIG. 13integrates functions of the baseband processor and the centralprocessing unit. A person skilled in the art may understand that thebaseband processor and the central processing unit may alternatively beindependent processors, and are interconnected by using technologiessuch as a bus. A person skilled in the art may understand that the userequipment may include a plurality of baseband processors to adapt todifferent network standards, the user equipment may include a pluralityof central processing units to enhance a processing capability of theuser equipment, and various components of the user equipment may beconnected by using various buses. The baseband processor may also beexpressed as a baseband processing circuit or a baseband processingchip. The central processing unit may also be expressed as a centralprocessing circuit or a central processing chip. A function ofprocessing the communications protocol and the communication data may beembedded into the processor, or may be stored in the storage unit in aform of a software program. The processor executes the software programto implement a baseband processing function.

For example, in this embodiment of the present invention, the antennaand a control circuit that have sending and/or receiving functions maybe considered as a transceiver unit 11 of the UE 10, and the processorhaving a processing function may be considered as a processing unit 12of the UE 10. As shown in FIG. 13, the UE 10 includes the transceiverunit 11 and the processing unit 12. The transceiver unit may also bereferred to as a transceiver, a transceiver machine, a transceiverapparatus, or the like. Optionally, a component that is in thetransceiver unit 11 and that is configured to implement a receivingfunction may be considered as a receiving unit, and a component that isin the transceiver unit 11 and that is configured to implement a sendingfunction may be considered as a sending unit. In other words, thetransceiver unit 11 includes the receiving unit and the sending unit.For example, the receiving unit may also be referred to as a receivermachine, a receiver, a receiver circuit, or the like, and the sendingunit may be referred to as a transmitter machine, a transmitter, atransmit circuit, or the like.

This application further provides a computer storage medium, includinginstruction(s). When the instructions run on a computer, the computerperforms a technical solution on a terminal side according to theforegoing method embodiments.

This application further provides a computer storage medium, includinginstruction(s). When the instructions run on a computer, the computerperforms a technical solution on a network device side according to theforegoing method embodiments.

This application further provides a computer program product. When thecomputer program product runs on a computer, the computer performs atechnical solution on a terminal side according to the foregoing methodembodiments.

This application further provides a computer program product. When thecomputer program product runs on a computer, the computer performs atechnical solution on a network device side according to the foregoingmethod embodiments.

A person skilled in the art may further understand that variousillustrative logic blocks and steps that are listed in the embodimentsof this application may be implemented by using electronic hardware,computer software, or a combination thereof. Whether the functions areimplemented by using hardware or software depends on a particularapplication and a design requirement of an entire system. A personskilled in the art may use various methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of theembodiments of this application.

The various illustrative logic units and circuits described in theembodiments of this application may implement or operate the describedfunctions by using a general-purpose processor, a digital signalprocessor, an application-specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or another programmable logic apparatus,a discrete gate or transistor logic, a discrete hardware component, or adesign of any combination thereof. The general-purpose processor may bea microprocessor. Optionally, the general-purpose processor may be anyconventional processor, controller, microcontroller, or state machine.The processor may be implemented by a combination of computingapparatuses, such as a digital signal processor and a microprocessor, aplurality of microprocessors, one or more microprocessors with a digitalsignal processor core, or any other similar configuration.

Steps of the methods or algorithms described in the embodiments of thisapplication may be directly embedded into hardware, a software unitexecuted by a processor, or a combination thereof. The software unit maybe stored in a RAM memory, a flash memory, a ROM memory, an EPROMmemory, an EEPROM memory, a register, a hard disk, a removable magneticdisk, a CD-ROM, or a storage medium in any other form in the art. Forexample, the storage medium may be connected to a processor, so that theprocessor can read information from the storage medium and writeinformation to the storage medium. Optionally, the storage medium may beintegrated into a processor. The processor and the storage medium may bedisposed in an ASIC, and the ASIC may be disposed in UE. Optionally, theprocessor and the storage medium may alternatively be disposed indifferent components of the UE.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof. When beingimplemented by using software, all or some of the embodiments may beimplemented in a form of a computer program product. The computerprogram product includes one or more computer instructions (sometimesmay alternatively be referred to as computer programs). When thecomputer instructions are loaded and executed on a computer, theprocedures or functions according to the embodiments of this applicationare all or partially generated. The computer may be a general-purposecomputer, a special-purpose computer, a computer network, or anotherprogrammable apparatus. The computer instructions may be stored in acomputer readable storage medium or transmitted from a computer readablestorage medium to another computer readable storage medium. For example,the computer instructions may be transmitted from a website, computer,server, or data center to another website, computer, server, or datacenter in a wired (for example, a coaxial cable, an optical fiber, or adigital subscriber line (DSL)) or wireless (for example, infrared,radio, or microwave) manner. The computer readable storage medium may beany available medium accessible to the computer, or a data storagedevice, such as a server or a data center integrating one or moreavailable media. The available medium may be a magnetic medium (forexample, a floppy disk, a hard disk, or a magnetic tape), an opticalmedium (for example, a DVD), a semiconductor medium (for example, asolid state disk Solid State Disk (SSD)), or the like.

In this application, the term “including” and a variant thereof mayrefer to non-limitative inclusion; the term “or” and a variant thereofmay refer to “and/or”. In this application, the terms “first”, “second”,and the like are intended to distinguish between similar objects but donot necessarily indicate a specific order or sequence. “A plurality of”in this application refers to two or more than two. The term “and/or”describes an association relationship between associated objects andrepresents that three relationships may exist. For example, A and/or Bmay represent the following three cases: Only A exists, both A and Bexist, and only B exists. The character “/” generally indicates an “or”relationship between the associated objects.

The content disclosed in this application is not limited to thedescribed embodiments and designs, but may further be extended to amaximum scope that is consistent with the principles of this applicationand new features disclosed in this application.

What is claimed is:
 1. A wireless communication method, comprising:receiving configuration information, wherein the configurationinformation comprises first uplink carrier information and second uplinkcarrier information, and wherein the first uplink carrier informationindicates that a first uplink carrier is a switching-from uplink carrierfor a sounding reference signal (SRS) carrier switching, the seconduplink carrier information indicates that a second uplink carrier is aswitching-to uplink carrier for the SRS carrier switching, and at leastone of the first uplink carrier and the second uplink carrier belongs toa cell comprising a supplementary uplink (SUL) carrier; and determining,based on the configuration information, the switching-from uplinkcarrier and the switching-to uplink carrier for the SRS carrierswitching.
 2. The method according to claim 1, further comprising:receiving downlink control information (DCI), wherein the DCI carriesaperiodic sounding reference signal (A-SRS) trigger indicationinformation and an uplink carrier identifier of the second uplinkcarrier.
 3. The method according to claim 1, wherein the first uplinkcarrier belongs to a switching-from cell that comprises an uplink (UL)carrier and the SUL carrier.
 4. The method according to claim 1, whereinthe first uplink carrier information comprises a cell identifier of aswitching-from cell to which the switching-from uplink carrier belongsand information indicating the switching-from uplink carrier.
 5. Themethod according to claim 4, wherein the information indicating theswitching-from uplink carrier comprises one or more of following: acomponent carrier index, an uplink index, a secondary cell SUL index, orinformation identifying a carrier.
 6. The method according to claim 4,wherein the information indicating the switching-from uplink carrierindicates that the switching-from uplink carrier is a UL carrier or theSUL carrier.
 7. The method according to claim 1, wherein the seconduplink carrier information comprises information indicating aswitching-to cell to which the switching-to uplink carrier belongs andinformation indicating the switching-to uplink carrier.
 8. The methodaccording to claim 1, wherein the configuration information furthercomprises an index of a carrier set comprising an uplink carrier that isnot used to transmit a physical uplink shared channel/physical uplinkcontrol channel (PUSCH/PUCCH) and an index of a carrier in the carrierset.
 9. A communications apparatus, comprising a receiver and aprocessor, wherein: the receiver is configured to receive configurationinformation, wherein the configuration information comprises firstuplink carrier information and second uplink carrier information, andwherein the first uplink carrier information indicates that a firstuplink carrier is a switching-from uplink carrier for a soundingreference signal (SRS) carrier switching, the second uplink carrierinformation indicates that a second uplink carrier is a switching-touplink carrier for the SRS carrier switching, and at least one of thefirst uplink carrier and the second uplink carrier belongs to a cellcomprising a supplementary uplink (SUL) carrier; and the processor isconfigured to determine, based on the configuration information, theswitching-from uplink carrier and the switching-to uplink carrier forthe SRS carrier switching.
 10. The communications apparatus according toclaim 9, wherein the receiver is further configured to receive downlinkcontrol information (DCI), wherein the DCI carries aperiodic soundingreference signal (A-SRS) trigger indication information and an uplinkcarrier identifier of the second uplink carrier.
 11. The communicationsapparatus according to claim 9, wherein the first uplink carrierinformation comprises a cell identifier of a switching-from cell towhich the switching-from uplink carrier belongs and informationindicating the switching-from uplink carrier.
 12. The communicationsapparatus according to claim 11, wherein the information indicating theswitching-from uplink carrier comprises one or more of following: acomponent carrier index, an uplink index, a secondary cell SUL index, orinformation identifying a carrier.
 13. The communications apparatusaccording to claim 11, wherein the information indicating theswitching-from uplink carrier indicates that the switching-from uplinkcarrier is a UL carrier or the SUL carrier.
 14. The communicationsapparatus according to claim 9, wherein the second uplink carrierinformation comprises information indicating a switching-to cell towhich the switching-to uplink carrier belongs and information indicatingthe switching-to uplink carrier.
 15. The communications apparatusaccording to claim 9, wherein when the second uplink carrier belongs tothe cell comprising the SUL carrier, the second uplink carrier is anon-SUL carrier.
 16. The communications apparatus according to claim 9,wherein when the first uplink carrier belongs to the cell comprising theSUL carrier, the first uplink carrier is a non-physical uplink controlchannel (non-PUCCH) carrier.
 17. The communications apparatus accordingto claim 9, wherein at least one of the first uplink carrier informationand the second uplink carrier information comprises a new carrierindicator field (NCIF) identifier.
 18. The communications apparatusaccording to claim 17, wherein the NCIF identifier comprises a cellidentifier and an uplink carrier identifier.
 19. The communicationsapparatus according to claim 9, wherein the configuration informationindicates a location of an uplink carrier in an information block ofuser equipment (UE)-group-level DCI, the uplink carrier is not used totransmit a physical uplink shared channel/physical uplink controlchannel (PUSCH/PUCCH), and the information block of the UE-group-levelDCI comprises at least one of SRS power control information, A-SRStrigger indication information, and uplink carrier identifierinformation of the uplink carrier that is not used to transmit thePUSCH/PUCCH.
 20. The communications apparatus according to claim 9,wherein the configuration information further comprises an index of acarrier set comprising an uplink carrier that is not used to transmit aPUSCH/PUCCH and an index of a carrier in the carrier set.
 21. Acomputer-readable storage medium comprising instructions which, whenexecuted by a processor, cause the processor to: receive configurationinformation, wherein the configuration information comprises firstuplink carrier information and second uplink carrier information, andwherein the first uplink carrier information indicates that a firstuplink carrier is a switching-from uplink carrier for a soundingreference signal (SRS) carrier switching, the second uplink carrierinformation indicates that a second uplink carrier is a switching-touplink carrier for the SRS carrier switching, and at least one of thefirst uplink carrier and the second uplink carrier belongs to a cellcomprising a supplementary uplink (SUL) carrier; and determine, based onthe configuration information, the switching-from uplink carrier and theswitching-to uplink carrier for the SRS carrier switching.
 22. Thecomputer-readable storage medium according to claim 21, wherein thefirst uplink carrier information comprises a cell identifier indicatinga switching-from cell to which the switching-from uplink carrier belongsand information indicating the switching-from uplink carrier.
 23. Thecomputer-readable storage medium according to claim 22, wherein theinformation indicating the switching-from uplink carrier indicates thatthe switching-from uplink carrier is a UL carrier or the SUL carrier.